ESP8266 Community Forum

- Thu Jun 25, 2015 6:00 pm #21698

I have one the COB style spots like on your blog (9w though). But when I try and dim it using a Mosfet (http://www.ti.com/lit/ds/symlink/csd18533kcs.pdf) I find that the supplied driver hums. Have you encountered something similar? The driver is a constant current type. Any ideas?

EDIT: After some more reading, it would seem that my 12k pull-down resistor was a bit much. Tried it with a 1.2k resistor and non as well, but seems I am having some issues. In theory, the mosfet should be able to dim a constant current supply as well right?

Ah no, I believe you will need a constant voltage power supply.

You need to measure the voltage the constant current supply is outputting at max brightness and then match that voltage with a constant voltage supply. Then using my dimmer design with mosfets you will be able to dimm to LEDs perfectly.

- Fri Jun 26, 2015 9:20 am #21762

I have one the COB style spots like on your blog (9w though). But when I try and dim it using a Mosfet (http://www.ti.com/lit/ds/symlink/csd18533kcs.pdf) I find that the supplied driver hums. Have you encountered something similar? The driver is a constant current type. Any ideas?

EDIT: After some more reading, it would seem that my 12k pull-down resistor was a bit much. Tried it with a 1.2k resistor and non as well, but seems I am having some issues. In theory, the mosfet should be able to dim a constant current supply as well right?

Ah no, I believe you will need a constant voltage power supply.

You need to measure the voltage the constant current supply is outputting at max brightness and then match that voltage with a constant voltage supply. Then using my dimmer design with mosfets you will be able to dimm to LEDs perfectly.

Alright! I will hop over to the other thread to try and better understand whats going on. If all else fails, will switch to a CV supply.
Btw, what do you use to power your COB chip?

- Wed Jul 08, 2015 3:05 pm #22792

Btw, what do you use to power your COB chip?

Ah, sorry I missed your reply. I use power supplies from China to power them. I measure the COB light at full power using the supplied power supply and then match it with a constant voltage power supply instead of the included constant current power supply.

From the 8 different COB LEDs I'm testing they all have a different voltage! So be sure to take correct measurements before you hook them up. I have a lab power supply which helps with it, but setting it 1 or 2 volt too high can easily blow the COB LED.

The one's I'm testing right now use 32v, one uses 38.5v and one uses 42v. The QuinLED v2 design handles it like a champ though. The onboard voltage regulator is dynamic, so even when dailing up or down the voltage to the board the ESP8266 doesn't fail!

- Tue Jul 26, 2016 3:12 pm #51540 I'm reviving this topic because I'm creating a new series of video's about QuinLED, my ESP8266 PWM WiFi LED dimmer which I use in combination with Domoticz to control my LED lighting.

The revive or revisit of the series will be done in several new blog posts with youtube videos detailing exactly, what it is, why I built it and the history of the PCB versions. In future videos I'll go through exactly what hardware you need, components to get, how to solder it and in more videos, how to program it and connect it to Domoticz to have a true lighting solution!

You can find the new post and video here: http://blog.quindorian.org/2016/07/esp8266-lighting-revisit-and-history-of-quinled.html/

If anyone has any questions or comments, you can leave them here or on my blog/youtube video!